Sleep and the Visual Environment of Wakefulness : A Psychobiological Study

Abstract

A critical evaluation of the equivocal findings from previous sleep
deprivation research revealed that a further study could be undertaken,
taking into consideration, the quality of measurement adopted, the
circadian variation and in particular, the context of sleep deprivation
A theory of sleep in man, based upon biological premises and orientated
towards the visual system was constructed. In order to provide a descriptive tool for sleep deprivation, a differential arousal schema
incorporating the concept of controlled and controlling events, was
evolved.

A methodological study investigated the effects of high and low intensity
input from the gross visual environment during 62 hours of sleep loss
upon six male subjects. A three phase design incorporated into a latin
square was used, with subjects undergoing oculomotor, cardiovascular,
respiratory and performance measurement every six hours. All night sleep
records were taken before and after sleep deprivation.

The data were carefully analysed with respect to circadian variation and
individual differences. The findings from the wakeful measures revealed
that under the condition of high visual intensity, the untoward effects
of sleep deprivation were substantially greater than for the. low intensity
condition as reflected by heart rate variation, respiratory
irregularity, binocular co-ordination and tracking performance. The
findings with physiological data, in particular with cardiovascular
measures, suggested that qualitative analysis was more likely to reveal
the effects of sleep deprivation. The arousal schema was able to describe
the sequence of changes exhibited by physiological and psychological
data. A possible phase shift with the circadian variation of body temperature was seen to be of considerable importance. After the high intensity compared with the low intensity condition, recovery sleep data revealed significant increases in SWS and REM density, with decreases in REM. These findings provided support for the sleep theory.

The binocular co-ordination measure appeared to be of potential use to
sleep deprivation research, and a further study was undertaken with
twelve subjects who underwent one night of sleep loss upon two occasions.
Although all subjects showed a change in the predicted direction, this
was significant with only half the subjects. A further small study to
investigate the concept of oculomotor innervation for REM, provided somewhat
obscure results which did not contradict the general sleep theory.

Date of Award	1972
Original language	English